I'm misophonic. I have a very peculiar response to some sounds, especially that of people chewing. A person could be eating across the room and I'll be twitching and pacing. Either that, or I get really mad because the sound is just grating on my nerves. Some people with misophonia have an almost PTSD-like reaction to the eating sound stimulus. Others, completely shut down. Psychologists theorize that it is a form of OCD, but it manifests differently in certain people.
...I also like to research for fun, in case you can't tell